Matching networks can help stabilize the
amplifier by keeping the source and load impedances in the appropriate range.
Impedance matching (or tuning) is an important issue for - Maximum power is
delivered when load is matched to line (assuming the generator is matched) -
Power loss is minimized. S/N- ratio of receiver components is increased. -
Amplitude and phase errors are reduced.

3) What
is function of input and output matching networks?

Input and output matching networks are needed
to reduce undesired reflections and improve the power flow capabilities.

4) What
are the parameters used to evaluate the performance of an amplifier?

Key parameters of amplifier, to evaluate the
performance are

i.Gain and gain flatness(in dB)

ii.Operating frequency and bandwidth (in Hz)

iii.Output power (in dB)

iv.Power
supply requirements (in V and A)

v.Input and output reflection coefficients (VSWR)

vi.Noise
figure (in dB)

5)Define transducer power gain.

Transducer power gain is nothing but the gain
of the amplifier when placed between source and load.

6)
Define Unilateral Power gain.

It is the amplifier power gain, when feedback
effect of amplifier is neglected i.e.S12=0.

7) What
is available Power Gain (GA) at Load?

The available power gain for load side matching
(TL = T*Out) is given as,

8)
Define Operating Power Gain.

The operating power gain is defined as “the
ratio of power delivered to the load to the power supplied to the amplifier”.

9) Write
a short note on feedback of RF circuit.

i.If |T|>1, then the magnitude of the return
voltage wave increases called positive feedback, which causes instability
(oscillator).

ii.If |T|<1, then the return voltage wave is
totally avoided (amplifier). It‟s called
as negative feedback.